Most of the experimental data strongly supports the existence of superconductivity in superhydrides. However, some of the experimental features are puzzling and seem to violate known standard superconducting properties. While some features support type-I superconductivity, others support type-II. This disparity shows the simultaneous coexistence of type-I and type-II. Another puzzling question is the high critical temperature with moderate electron-phonon coupling. Theoretical calculations suggest that the dimensionless electron-phonon coupling \(\Lambda \sim 2\)  in superhydrides have moderate values [1]}. In general, the width of the resistive transition in the presence of a magnetic field is expected to be large for type-II superconductors. For example, the width of the resistive transition in MgB\(_2\)  at a magnetic field \(H = 0.15 H_{c2}\)  is about \(\Delta T_C/T_C \sim 0.15 \%\) . In contrast, the resistive transition width of C-S-H at the same magnetic field is smaller than that of MgB\(_2\)  by a factor of about 50 [2]}, [3]}. This narrow transition width in the C-S-H system and other superhydrides apparently suggests that these are type-I superconductors [4]}. Further, using an experimental sample size and measured resistance, the resistivity of the C-S-H system was calculated by Dogan et al [5]}. The calculation was done using a resistive formula derived from the four-point van der Pauw procedure. The calculated resistivity was found to fall into the poor metal/semimetal range above the critical temperature. The resistivity below the critical temperature was found to be 2-3 orders of magnitude lower falling into the typical metal range. In addition, by analyzing resistivity broadening experimental data, Hirsch et al [6]} argued that the zero-temperature critical current density in C-S-H systems is five orders of magnitude larger than that of standard superconductors. The experimental data reported in Ref. [7]} for the H\(_3\) S system indicates that the effective mass of the electrons at pressure 150 GPa is larger than the expected effective mass by a factor of about 10 [8]}. This mass enhancement is not consistent with the electron-phonon interactions estimated for H\(_3\) S, nor the theoretical calculations [9]}, [10]}, [11]}, [1]}, [13]}, [14]}, [15]}. Due to the fact that these experimental features are not able to be explained using the standard superconductivity theories, a series of recent articles argue that the superhydrides under pressure are either a unique kind of superconductors or not superconductors at all [3]}, [5]}, [6]}, [8]}, [20]}.
